This invention relates generally to an initiator assembly for use in inflator devices. More specifically, the invention relates to an integral initiator assembly such as for use in the inflation of inflatable devices such as inflatable vehicle occupant restraint airbag cushions used in inflatable restraint systems.
It is well known to protect a vehicle occupant using a cushion or bag, e.g., an “airbag cushion,” that is inflated or expanded with gas such as when the vehicle encounters sudden deceleration, such as in the event of a collision. In such systems, the airbag cushion is normally housed in an uninflated and folded condition to minimize space requirements. Upon actuation of the system, the cushion begins to be inflated, in a matter of no more than a few milliseconds, with gas produced or supplied by a device commonly referred to as an “inflator.”
Many various inflator devices have been disclosed in the art for the inflating of one or more inflatable restraint system airbag cushions. One category of such inflator devices is often referred to as “compressed gas inflators” and refers to various inflators which contain a selected quantity of compressed gas. For example, one particular category of compressed gas inflator, commonly referred to as a “stored gas inflator,” simply contains a quantity of a stored compressed gas which is selectively released to inflate an associated airbag cushion.
A second category of compressed gas inflator, commonly referred to as “hybrid inflators,” typically supplies or provides inflation gas as a result of a combination of stored compressed gas with combustion products resulting from the combustion of a gas generating material.
Specific types of compressed gas inflator devices include those commonly referred to as “blow down” and those referred to as “direct opening” inflation systems. In a blow down inflation system, a pyrotechnic or other selected material is commonly burned or otherwise reacted to create a build-up of pressure within a compressed gas storage chamber such as to result in the rupture or release of inflation gas therefrom when the internal pressure reaches a predetermined level or range. For example, upon actuation of an initiator device, a gas generant material is heated resulting in the release of gas. The resulting increase in pressure ruptures a sealing disk, thereby releasing stored inflation gas. The released inflation gas exits the inflator device through exit holes previously blocked by the ruptured disk.
In contrast, in a direct opening type inflation system, compressed gas is commonly released as a result of the movement of a mechanical opening device such as an associated projectile or piston member. For example, the actuation of an initiator device in turn actuates gas generant material which produces gas. The increase in gas pressure causes a projectile to propel through a sealing disk, thereby releasing stored inflation gas. The released inflation gas exits the inflator device through exit holes previously blocked by the ruptured disk.
The prior art generally discloses both blow down and direct opening inflator devices beneficial for use in airbag installations. However, compressed gas inflators, such as blow down and direct opening inflators, typically require undesirably complicated and/or considerably multiple component assemblies which can undesirably increase manufacturing steps and costs. The need for such relatively complicated initiator assemblies and initiator assembly installations is often due to the utilization of a generally “standard” initiator canister being used in various inflator device configurations. Initiator assemblies known in the art generally adapt typically “standard” initiator canisters to be used in new inflator design configurations.
There is a need for a more simplified inflator device that can be more easily and inexpensively produced. Further, there is a need for a more simplified inflator device which can be used in various airbag installations and in various vehicular types. There is further also a need for a single inflator device design that can be easily configured as a blow down or direct opening inflator device.